At present, the space available under the engine bonnet of vehicles is ever more restricted, particularly around the engine block, favouring integration of the functions to be achieved in order to reduce size, while continuing to maintain their quality and operational life, on which the reliability of the vehicle's operation depends.
In addition, in terms of the development and manufacture of internal combustion engine vehicles, the present trend is no longer think to in terms of isolated elements, namely components or parts, but in terms of assemblies, units or modules, each fulfilling an overall function or several interdependent elementary functions.
This is the case in particular for the overall air inlet function, whether the air is turbocompressed or not, which usually incorporates the function of admitting fresh air and the function of recycling or reinjecting at least part of the exhaust gases, in a way that can be regulated and controlled.
An air inlet module that combines these two functions normally includes, in one structural unit, on the one hand, an inlet manifold or distributor with a supply conduit, on the other hand, a circuit for the controlled reinjection and mixing of exhaust gases in the fresh air admitted by the manifold and, finally, a gas/liquid heat exchanger designed to cool the exhaust gases before they are mixed with the possibly turbocompressed, air admitted, said exchanger being composed substantially of several exhaust gas circulation manifolds mounted in a hollow container forming a tank and receiving a cooling liquid circulating around said circulation manifolds. Different embodiments of such an air inlet module are already known, but these known embodiments have, however, drawbacks and limitations preventing a satisfactory response to the demands made.
Among these limitations can be mentioned, in particular, the difficulty of manufacture, resulting from the very large number of elementary components to be assembled, sensitivity to vibrations and a not inconsiderable excess weight due to these numerous assemblies, and the resulting large size.
Thus, through document EP-A-1 375 896, a module of the aforementioned type is known, incorporating a plate for distributing, mixing and conveying the different fluid gases (fresh air and exhaust gases), in which circulation channels are provided.
Nevertheless, this module still has numerous assembly zones for the many different constituent parts and is large in size.